title: Two new isoflavones from Ceiba pentandra and their effect on cyclooxygenase-catalyzed prostaglandin biosynthesis.
abstract: The new isoflavone glucoside vavain 3'-O-beta-d-glucoside (1) and its aglycon, vavain (2), were isolated from the bark of Ceiba pentandra, together with the known flavan-3-ol, (+)-catechin, These novel structures were elucidated by one- and two-dimensional NMR experiments and by MS, IR, and UV spectroscopy as 5-hydroxy-7,4',5'-trimethoxyisoflavone 3'-O-beta-D-glucoside (1) and 5,3'-dihydroxy-7,4',5'-trimethoxyisoflavone (2), respectively. The compounds were isolated following bioactivity-directed fractionation, using a cyclooxygenase-1-catalyzed prostaglandin biosynthesis assay in vitro, in which compounds 1 and 2 and (+)-catechin exhibited IC50 values of 381, 97, and 80 microM, respectively (standard: indomethacin, IC50 1,1 microM). When further tested for their inhibitory effects on cyclooxygenase-2-catalyzed prostaglandin biosynthesis, 1 and 2 were found to be inactive (IC50 > 1200 and > 900 microM, respectively).
authors.affiliation: Department of Pharmacy, Uppsala University, Sweden.
authors.forename: Y
authors.initials: Y
authors.lastname: Noreen
authors.forename: H
authors.initials: H
authors.lastname: el-Seedi
authors.forename: P
authors.initials: P
authors.lastname: Perera
authors.forename: L
authors.initials: L
authors.lastname: Bohlin
mesh_terms: D000818:Animals; D002417:Cattle; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology*; D005960:Glucosides / Q000302:isolation & purification / Q000494:pharmacology*; D007527:Isoenzymes / Q000378:metabolism; D007529:Isoflavones / Q000302:isolation & purification* / Q000494:pharmacology*; D009682:Magnetic Resonance Spectroscopy; D019441:Plant Epidermis / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry*; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism; D011453:Prostaglandins / Q000096:biosynthesis*; D016339:Spectrometry, Mass, Fast Atom Bombardment; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet
chemical_list: D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors; D005960:Glucosides; D007527:Isoenzymes; D007529:Isoflavones; D011453:Prostaglandins; C110785:vavain; C110786:vavain 3'-O-glucoside; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D011451:Prostaglandin-Endoperoxide Synthases